This is a small trailer I made for my mountain bike. It was made from recycled materials and some other parts that can be picked up at the hardware store for $10 or less.
Step 1: Main Body
First, get a storage bin with a lid. Then you need ply-wood. Cut the first piece of ply-wood to fit snugly inside the bin. Cut the second piece larger than the bottom of the bin. Next, make a "sandwich" of Ply-wood one, the bin, then the 2nd piece of ply wood centered on the bottom of the bin. Screw it together with screws.
Step 2: Wheel Mounts
For this step you will need 2 brackets. They should have holes in them( both for mounting the bike tires and for bolting it to the main body)If the holes are not big enough to fit the wheels, make them bigger.Bolt them to the 2nd (bottom) piece of ply-wood. Now put the bike wheels on like a normal bike.
Step 3: Hitch (bikes part)
For this you need a piece of metal that is strong but that you can bend. Bend it into a "U" shape. In the middle and on the two ends, make a hole. I used a garden hose hanger for this step but you van use any strong bendable metal.Then Screw it on to your BIKE right above the wheel mount.
Step 4: Hitch (traikers part)
For this you will need a piece of metal with a "L" shape. Mount the long part of the "L" to the trailer with the short part hanging off the front of the trailer, this part will form the removable hitch, the short part will go through the hole in the "U" it the previous step.
Step 5: Try it out
You may need to make minor agustments as you test your new bike trailer. HOPE I HELPED!